Valid Thursday March 02, 2017 to Monday March 13, 2017
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EST February 27 2017Synopsis
: Early in the period, a series of
surface low-pressure systems are forecast to move across the northern tier of
the U.S. Surface low pressure is forecast to pass north of northeast mainland
Alaska as its trailing cold front moves over the region Mar 2-3. Another area
of surface low pressure is expected near the Alaska Panhandle on those same
dates. Cold surface high pressure is forecast to dominate much of the rest of
mainland Alaska and the Aleutians into the week-2 period.
Summary For Thursday March 02 - Monday March 06:
- Periods of heavy snow for parts of the Olympics
and Cascades, Thu-Sat, Mar 2-4.
- Periods of heavy snow for parts of the Bitterroots and Northern Rockies,
Fri-Sun, Mar 3-5.
- Heavy precipitation for parts of Northern California and western Oregon,
Sat-Sun, Mar 4-5.
- Periods of much below normal temperatures for parts of central and southern
mainland Alaska and the Alaska Panhandle, Thu-Mon, Mar 2-6.
- High winds for parts of northeast mainland Alaska, Thu-Fri, Mar 2-3.
- Heavy snow for parts of the southern Alaska Panhandle, Thu-Fri, Mar 2-3.
- Flooding occurring or imminent, likely, or possible across portions of the
Great Lakes, the Mississippi Valley, the northern and central Plains and the
Northern Great Basin.
- Slight risk of much below normal temperatures for much of the Alaska
Panhandle, mainland Alaska, and the Aleutians, Tue-Mon, Mar 7-Mar 13.
- Moderate risk of much below normal temperatures for most of mainland Alaska
and the Aleutians, Tue-Sat, Mar 7-Mar 11.
- High risk of much below normal temperatures for parts of southern and
central mainland Alaska and the Alaska Peninsula, Tue-Wed, Mar 7-8.
- Severe Drought across the Central Plains, the Lower Mississippi Valley, the
Tennessee Valley, the Mid-Atlantic, California, the Southeast, the Southern
Appalachians, the Southern Plains, and the Southwest.
A series of low pressure systems at the surface and aloft are expected to
dominate much of the northern tier of the U.S. Mar 2-5. Periods of heavy snow
(in excess of 6 inches in 24 hours) are expected for parts of the Olympics and
Cascades (Mar 2-4) and for parts of the Bitterroots and Northern Rockies Mar
3-5. Heavy precipitation (rainfall exceeding 2 inches in 24 hours at lower
elevations, snowfall exceeding 8 inches in 24 hours at higher elevations) is
anticipated for parts of Northern California and western Oregon Mar 4-5.
Low pressure passing north of mainland Alaska is expected to lead to high
winds (speeds in excess of 35 knots) for parts of northeast mainland Alaska Mar
2-3. The combination of high winds, and falling or blowing snow is anticipated
to cause blizzard-like conditions for part of the region. Low pressure near the
Alaska Panhandle is expected to cause heavy snow (amounts in excess of 12
inches in 24 hours) for parts of the southern Alaska Panhandle Mar 2-3. The
snow amounts anticipated are marginal for a heavy snow hazard, but the shape
was included since snowfall is likely even at the lowest elevations. Cold high
pressures is forecast to lead to periods of much below normal temperatures
(negative anomalies in excess of 20 degrees F) for parts of central and
southern mainland Alaska and the Alaska Panhandle Mar 2-6.
Onshore flow is forecast to lead to precipitation near the southeast Texas
coast but the heaviest rainfall is currently expected to remain offshore so no
hazards are currently anticipated.
Low pressure near the Northern Plains Mar 6 may lead to wintry
precipitation for parts of the region but large model spread precludes the
specification of a hazard shape at the current time. For Tuesday March 07 - Monday
Riding is forecast west of Alaska with troughing expected over
mainland Alaska. This flow pattern favors much below normal temperatures for
much of Alaska. The GEFS reforecast probabilistic temperature tool indicates a
slight risk of much below normal temperatures for much of the Alaska Panhandle,
mainland Alaska, and the Aleutians Mar 7-13, a moderate risk of much below
normal temperatures for most of mainland Alaska and the Aleutians Mar 7-11, and
a high risk of much below normal temperatures for parts of southern and central
mainland Alaska and the Alaska Peninsula Mar 7-8.
According to the U.S. Drought Monitor valid on February 21, severe drought
is designated across parts of California, Arizona, the Great Plains, Arkansas,
south Texas, and the eastern U.S. Coverage of severe, or greater intensity,
drought throughout the continental U.S. remained nearly steady at 3.31 percent.
California, to the north of Point Conception, is free of long-term severe
Forecaster: Randy Schechter
Click here to see a display of the GFS Ensemble Forecasts
Please consult local NWS Forecast Offices for short range forecasts and region-specific information.